I hope I'm not too late to help you. I just noticed your post.
I'm in the final stages of building my new workshop/barn. The workshop portion is 30x40x14'. I used the Visual 3D online tool:
http://www.visual-3d.com/tools/interior/
to layout my lights. I used the Lights of America 8140SE2-WH5-29 LED shop lights from Sam's Club. Visual 3D didn't have these lights, but the Lithona LBL4 40L EZ1 LP850 seems to have similar specs, so I did my planning using that lamp. My goal was to get close to 100 foot-candles, 3 feet off the ground.
My lighting layout allowed for 40 of these fixtures (8 rows of 5), basically one for each 5x5' area of ceiling. (Due to a stairway cut-out, I only ended up with 35 of them in the shop.) Visual 3D estimated that I'd have about 90 f-c of light with that setup. After install, with bare OSB walls, my phone's light meter app says I'm getting 117 f-c in the middle of the shop with all lights on. With only the four "convenience" lights on, I'm getting about 17 f-c. The entire room pulls about 13A. At our current rate, it costs about 12 cents per hour to light the workshop.
Because my shop will be used for automechanics, woodworking, and perhaps parties, the light layout really isn't task-oriented, except that I was careful to make a layout that would still throw light around & between the 10x12' garage doors when they're open. The lights hang within 2' of every wall. With all lights on & the garage doors closed, the lighting is very uniform. With that many fixtures, there are no discernible shadows. I may still put some under-cabinet strip lights by my workbench if it ends up being necessary, but I kind of doubt it will be.
The ceiling will remain bare, kraft-faced insulation. I had originally planned to paint the walls white, but even that may not be necessary. It's not like I'll ever be able to see the bottom half of the walls once I move all my junk in there, anyway. I suppose painting the top 6-8' might help, though.
I absolutely love the light out there, and every visitor is also amazed. I'd definitely recommend my setup to a similar shop like yours.